Feed regulator for carburetors



Patented Aug. 1, 1939 FEED REGULATOR FOR CARBURETORS Fred J. Sachs, SanMateo, Calif., assignor to Dolly Purdy, San Mateo, Calif.

Application October 17, 1936, Serial No. 106,143

9 Claims. (01. 15846.5)

UNITED STATES PATENT OFFifiE pump for feeding gasoline to the carburetorand consists in its main features of means interposed between the pumpand the carburetor for obtaining the objects desired.

One of the objects of my invention is to provide a reservoir between thefuel pump and the carburetor and control means causing feed from thereservoir to the carburetor to stop when the level in the reservoirsinks below a predetermined point. Further feeding requires an act onthe part of the driver so that his attention will be called to the factthat his supply of gasoline is running low and he may stop at thenearest service station for securing a new supply.

Another object of the invention is to provide an air cham'ber betweenthe carburetor and the pump which permits vapors formed in the fuelline, usually through excessive heat to escape thereinto and to bevented therefrom.

Another object of the invention is to regulate the pressure at which thefuel is delivered to the carburetor so as to have the pressure remainrelatively constant and stable instead of varying with the speed of thepump.

Another object of the invention is to provide means whereby the pressurewhile remaining constant for different pump speeds, may be varied orregulated to suit different operating conditions.

Further objects and advantages of my invention will appear as thespecification proceeds.

The preferred forms of my invention are illustrated in the accompanyingdrawing in which Figure 1 shows a vertical section through one form ofmy invention,

Figure 2 a vertical section through a modified form of my invention, and

Figure 3 an enlarged detail view of the lower left-hand portion shown inFigures 1 and 2.

While I have shown only the preferred forms of my invention I wish tohave it understood that various changes or modifications may be madewithin the scope of the claims hereto attached without departing fromthe spirit of the invention.

In the form shown in Figures 1 and 2 my feed regulator consists of atank I having an intake opening 2 connecting through a pipe 3 with thefuel pump 4 and having a discharge opening ii connecting through atubefi with the carburetor 'i As applied to a motor vehicle, the pumpwill draw on a larger gasoline tank usually placed in the rear of thevehicle while the carburetor is connected to the intake manifold of theengine. The tank I, especially in the form shown in Figure 1, should bemounted higher than the carburetor so as to feed by gravity, while theposition of the pump is optional as long as it delivers gasoline fromthe main fuel supply to the tank l The intake opening 2 is controlled bya valve 8 which is carried by a float 9. The latter closes the intakevalve when the level of the gasoline reaches a predetermined maximumlevel as indicated by the dotted line Hi. The discharge of gasolinenormally takes place through the overflow pipe I i, the upper end ofwhich extends to within close proximity of the maximum level while itslower end connects with the outlet 5.

Thus, in normal operation, the float maintains the fuel in the tank at aconstant level and fuel is delivered to the carburetor at constantpressure through the overflow pipe It, the pressure depending upon therelative height of the fuel level i above the carburetor.

If, for some reason, the fuel supply furnished by the pump stops, as forlack of fuel in the main tank of the automobile or for failure of thepump to properly function, the fuel level in the tank l supply to takehim to the nearest service station.

To render the reserve supply available I provide'a second dischargeopening i2 near the bot- The upper end of the rod M is connected to m"acrank lever l9 and the latter may be operated $5 from the driver'sseat through a handle 20 on the dashboard and a cable 2! connecting thehandle with the lever. When the rod is raised for opening the valve acatch 22 pivoted in the lug 23 depending from the top of the tank ismoved underneath the collar l8 under the influence of the weight of along lever arm 24 and automatically holds the valve in open position.

The opening of the valve opens up a new supply for the carburetor. Asthe level of the reserve supply sinks the float sinks until it reaches astop 25 which is in the nature of a spider secured in the tankunderneath the float and which may also be used as a support for theoverflow pipe and for the rod M. The entire supply of the tank is nowavailable and will probably be sufficient to carry the vehicle to asupply station.

After the main tank has been filled again and the pump is set inoperation, the tank 1 begins to fill and as it rises to a position nearthe maximum height it lifts the float and as the float rises it strikesthe lever arm 24 and releases the catch 22 so that the spring I! returnsthe valve l3 to its normal and closed position, while the tank feeds thecarburetor through the overflow pipe ID.

The lever arm 24 is of considerable length and, its outer end descendsconsiderably when the catch engages underneath the collar l8 so that itwill be struck by the float before the maximum level has been reached bythe rising fuel. The collar I8 is shown as being tapered and when itrides downward along the catch it has a tendency to throw the latteroutward and to thereby raise the arm 24 well away from the float.

A filler cap 25 is provided in the top of the tank I and is formed witha vent 26 and a check valve 21 which allows air to escape but whichwould close against rising liquid so as to prevent leaking in case thefloat control should fail and the tank should fill beyond the maximumlevel.

The form thus far described depends on gravity feed and the pressure atwhich the fuel is delivered at the carburetor depends upon the level ofthe gasoline in the tank. Since the level is constant under normaloperating conditions, the pressure at which the gasoline is delivered tothe carburetor is constant.

It frequently happens that, under the influence of excessive heat, aswhen traveling in the desert or when the engine becomes too hot, thegasoline in the feed pipe begins to vaporize and interferes with theproper feeding of gasoline to the carburetor. This is known as vaporlock and becomes quite troublesome, especially when traveling underunusual conditions where assistance is not easily obtained. My inventiondoes away with vapor locks since any vapor formed in the fuel line willnaturally rise into the air chamber above the gasoline in the tank I andwill disappear through the vent 26.

In the form shown in Figure 2 a special feature is added to that ofFigure 1, namely means for providing pressure in the air chamber, sothat the delivery at the carburetor may be under pressure in addition tothat of the head of liquid, and means permitting the pressure to beregulated. In most points this construction is the same as in Figure land the changes consist in the elimination of the vent from the fillercap 25' and the substitution of a movable and adjustable vent inconnection with the rod l4.

It will be noted that the latter is formed with a groove or slot 28 inthe upper portion thereof. This groove or slot is dimensioned so thatwhen the rod [4 is in valve closing position, as shown in the figure,the upper end of the groove is underneath the top of the packing gland29 and is closed thereby so that no venting takes place. When the valveis raised, however, the upper end of the groove rises above the glandwhile the lower end is still in communication with the inside of thetank so that now the groove is operative as a vent.

This construction has the following effect: When the valve I3 is openedfor drawing on the reserve supply, air is free to enter through the ventto fill the vacuum caused by the receding liquid. When the tank isfilled again, with the valve l3 still open, the rising liquid pushes theair through the vent until the float 9 trips the catch and therebycloses the valve l3. This brings the slot or groove 28 below the glandso that the tank is now hermetically sealed and the air remaining in thetank will be compressed by the further rise of the liquid until thelatter reaches its maximum level. Thus the body of liquid is underpressure during normal operation.

The degree of pressure depends, of course, upon the amount of aircompressed and the latter depends upon the timing of the vent valve.sooner the vent valve closes the more air will be trapped and the laterit closes, the less air.

To permit the amount of air to be regulated I mount the pivot 30 for thecatch 22, on a movable rod 31 which is threaded into a sleeve 32rotatably' mounted in the top of the tank and held against endwisemotion so that the rod may be lowered and raised by turning the sleeve.The pivot for the lever 19 may be mounted on the same rod withoutaffecting the operation of the lever,

The lowering of the rod causes an earlier closing of the vent and alarger amount of trapped air with a corresponding increase in pressure,while the rising of the rod causes a delayed closing of the vent andless air trapped with a correspondingly smaller degree of pressure.

I claim:

1. In combination, a carburetor, a fuel pump, a tank having an intakedirectly connected to the pump and an outlet directly connected to thecarburetor for normally feeding the same, control means for the outletadapted to build up a reserve fuel supply in the tank, means forautomatically shutting off the feed from the tank to the carburetor whenthe reserve fuel supply sinks below a predetermined level, manuallycontrolled means for releasing the reserve fuel supply for feeding thecarburetor, automatically operating means for holding the latter meansin fuel releasing position and automatically operating means forreturning said means to non-releasing position when the level of thefuel in the tank again rises above the predetermined fuel level.

2. In combination, a tank for holding fuel, an outlet for the same, avalve for the outlet having means urging the valve into closed position,means for opening the valve, a catch for holding the valve in openposition and a float riding on the fuel having means for releasing thecatch when the fuel rises to a predetermined height.

3. In combination, a tank for holding fuel, an outlet for the same, avalve for the outlet having a rod extending through the top of the tank,a collar on the rod, spring means bearing on the collar and urging thevalve into closed position, means for longitudinally moving the rod foropening the valve, a catch engageable with the collar for The holdingthe valve in open position, an arm projecting from the. catch and afloat riding on the fuel adapted to raise the arm for releasing thecatch when the fuel rises to a predetermined height.

4. In combination, a tank for holding fuel, an outlet for the same, avalve for the outlet having a rod extending through the top of the tank,a collar on the rod, spring means bearing on the collar and urging thevalve in closed position, means for longitudinally moving the rod foropening the valve, a catch engageable with the collar for holding thevalve in open position, an arm projecting from the catch and a floatriding on the fuel adapted to raise the arm for releasing the catch whenthe fuel rises to a predetermined height, the collar being tapered toswing the catch outward for lifting the arm away from the float.

5. In a reserve fuel supply, a tank having a feed inlet and means forfeeding fuel therethrough, a valve for the inlet having a float forclosing the same when the fuel reaches a predetermined level, a vent forthe tank and means operated by the float prior to the closing of thefuel inlet valve for closing the vent whereby a pressure is built up inthe tank.

6. In a reserve fuel supply, a tank having a fuel inlet and means forfeeding fuel therethrough, a valve for the inlet having a float forclosing the same when the fuel reaches a predetermined level, a vent forthe tank and means operated by the float prior to the closing of thefuel inlet valve for closing the vent whereby a pressure is built up inthe tank, the latter means being adjustable for predetermining the levelat which the float closes the event and for thereby regulating thepressure obtained.

'7. In combination, a tank for holding fuel and. having a fuel outlet, avalve for the outlet, means for seating the valve to close the outlet, acatch engageable with the valve for holding the valve in open position,an arm projecting from the catch, and a float riding on the fuel andpositioned to raise the arm for releasing the catch when the fuel in thetank rises to a predetermined height and means for guiding the floatwith freedom of limited vertical movement.

8. In combination, a tank for holding a fuel supply and having an inletand an outlet, means for supplying fuel to the tank through the inlet, avalve for closing the inlet and having a float for operating the valve,a valve for the outlet having means to close the same, means for openingthe outlet valve, a catch engageable with the outlet valve to hold thelatter in opened position, and means operated by the float to releasethe catch when the fuel in the tank rises to a predetermined height.

9. In combination, a tank for holding a fuel supply having .a fuelintake, a fuel outlet and a vent, valves for the intake, outlet and ventand a float in the tank having means for controlling all three of thevalves.

FRED J. SACHS.

